Michael Keaton recalls how his workout regime sparked a priceless reaction from his co-star, Jack Nicholson, while filming 1989’s Batman.

Michael Keaton recently spoke about working out for his role as Bruce Wayne in DC’s Batman, stating that he “approached it totally wrong” after hearing Jack Nicholson’s reaction. Batman was one of the earliest blockbuster superhero movies, turning the genre into a magnet for actors looking to get a big break in Hollywood.

Today’s actors now tend to put a lot of effort into embodying their comic book roles. This was also the case for Michael Keaton, who engaged in a workout regime to better convey Bruce Wayne’s build in the Batman movie.

Keaton recalled in an interview with GQ that his co-star, Jack Nicholson, reacted to his exercise regime saying, “What are you doing that for?” This is something that Keaton would later acknowledge, as bulking out ironically made acting in the constrictive Batman suit more uncomfortable.

As Keaton explained, if he kept the weight off, he would have had more “room to breathe” in Batman’s Batsuit. He clarified, however, that it was at least useful in helping him “carry” the suit during shooting, as the outfit was unsurprisingly quite heavy.

No DC character has been adapted to film more than Batman. As such, here are the chronological and release orders of each and every Batman movie.

How Michael Keaton’s Superhero Workout & Physique Is Different To Today’s Actors

Superhero Actors Like Hugh Jackman & Henry Cavill Have Famously Bulked Up For Roles

Some of Hollywood’s most famous body transformations have emerged from actors throwing themselves into their roles as superheroes.

Nowadays, getting shredded for a superhero role is practically par for the course. Some of Hollywood’s most famous body transformations have emerged from actors throwing themselves into their roles as superheroes. Keaton’s own Batman successor, Christian Bale, is one of the most famous among these, with his metamorphosis from playing the emaciated Trevor Reznik in The Machinist to the buff Bruce Wayne in Batman Begins in just six months being a particularly memorable show of his dedication. This would end up paying dividends, as Bale is now among the most iconic actors to play Batman.

It is inadvisable to imitate the rapid body transformations undergone by many superhero actors, who, for the most part, have access to immense resources that most others cannot access.

This is a far cry from Keaton’s pioneering tenure as a superhero. For some roles, like Tom Holland’s Spider-Man, maintaining the right physique is part of the job description, often in aid of the “shirtless scene” present in many modern superhero movies. The same was not the case for superhero actors in previous decades. Keaton’s attempts to emulate the brawny physique of his character were instead a product of his dedication to the role, which, while admirable, was not a necessary part of the job at the time.

Not every modern superhero movie has this requirement, however. For example, Kumail Nanjiani, who played Kingo in Eternals, was not required to undergo the strict training regime that he ended up taking on for his role. Other actors in modern superhero movies can also rely on CGI to bulk them up, which is not a privilege that Keaton had in Batman.